#include <bits/stdc++.h>
#include<iostream>
#include<iomanip>
#include<string>
#include<algorithm>
#include<vector>
#include<set>
#include<list>
#include<queue>
#include<math.h>
#include<bitset>
using ll = long long;
using namespace std;

int main()
{
    ll n;
    vector<ll> paken(1e6+1), pakenken(1e6+1), pa(1e6+1);
    cin >> n;
    paken[0] = 0;
    paken[1] = 1;
    pa[0] = 0;
    pa[1] = 0;
    pakenken[0] = 0;
    pakenken[1] = 0;
    for (int i = 2; i < 1e6+1; i++){
        pa[i] = (paken[i-1] + pakenken[i-1])%(1000000000+7);
        paken[i] = (pa[i-1])%(1000000000+7);
        pakenken[i] = (paken[i-1])%(1000000000+7);
    }
    cout << (pa[n] + paken[n] + pakenken[n])%(1000000000+7) << endl;
}